Hi,
I'm trying to open a file, and if the user hasn't given an extension, adding
one, but I can't find out what exception to use. If I leave off the rescue
statements, then I see ENOENT, so try using that, but get a NameError -
ENOENT is the Unix error, not Ruby's. So, what is the exception for a
missing file on IO.foreach, and how in general can I get a list of
exceptions or find out which is the right one to use?
eg:
if $include_header
orig_hdr_fname=header_fname
begin
IO.foreach(header_fname) do |hdr_line|
# Allow comments in header files:
opfile.write(hdr_line) if hdr_line !~ /^\s*#/
end
rescue IOError <---- THIS IS THE PROBLEM
header_fname=header_fname+"frt"
printf("Error reading header file %s - trying
%s\n",orig_hdr_fname,header_fname)
retry
rescue => err
printf("Error opening header file %s\n",err)
exit(BAD_FILE)
end
Thanks
···
--
Graham Nicholls
With Linux, the answer's always "Yes"
On Fri, 2 Jul 2004 20:12:51 +0900, Graham Nicholls <graham@rockcons.co.uk> wrote:
I'm trying to open a file, and if the user hasn't given an extension, adding
one, but I can't find out what exception to use. If I leave off the rescue
statements, then I see ENOENT, so try using that, but get a NameError -
ENOENT is the Unix error, not Ruby's. So, what is the exception for a
missing file on IO.foreach, and how in general can I get a list of
exceptions or find out which is the right one to use?
ENOENT is the Unix error, not Ruby's. So, what is the exception for a
missing file on IO.foreach, and how in general can I get a list of
exceptions or find out which is the right one to use?
* Graham Nicholls <graham@rockcons.co.uk> [0723 13:23]:
Austin Ziegler wrote:
>
>> ENOENT is the Unix error, not Ruby's. So, what is the exception for a
>> missing file on IO.foreach, and how in general can I get a list of
>> exceptions or find out which is the right one to use?
>
> Try rescuing Errno::ENOENT.
Out of interest, is there anyway of knowing what exceptions a given
class can raise?
I'd expect not, but I've been wrong before (as any regulars on this list
will know).
···
--
I haven't lost my mind; I know exactly where I left it.
Rasputin :: Jack of All Trades - Master of Nuns
As far as I know, no. However, I have also read that the "promised"
list of exceptions (cf Java) is more problematic than useful (ISTR
something on Joel on Software about it). However, using the classtree
method (http://www.rubygarden.org/ruby?ASCIIClassHierarchyGenerator\),
you can call:
class_tree(Exception, false, false)
And get a tree of possible exceptions. That's where I found Errno::ENOENT.
-austin
···
On Fri, 2 Jul 2004 21:48:45 +0900, Dick Davies <rasputnik@hellooperator.net> wrote:
Out of interest, is there anyway of knowing what exceptions a given
class can raise?
I'd expect not, but I've been wrong before (as any regulars on this list
will know).
these are most of the errors, all the Errno::xxx errors are made by
SystemCallError:
~ > cat syserr.rb 255.times do |errno|
se = SystemCallError.new(errno)
next if se.message[%r/unknown error/io]
printf "%-3.3d : %s\n", errno, se.inspect
end
~ > ruby syserr.rb
000 : #<SystemCallError: Success>
001 : #<Errno::EPERM: Operation not permitted>
002 : #<Errno::ENOENT: No such file or directory>
003 : #<Errno::ESRCH: No such process>
004 : #<Errno::EINTR: Interrupted system call>
005 : #<Errno::EIO: Input/output error>
006 : #<Errno::ENXIO: No such device or address>
007 : #<Errno::E2BIG: Argument list too long>
008 : #<Errno::ENOEXEC: Exec format error>
009 : #<Errno::EBADF: Bad file descriptor>
010 : #<Errno::ECHILD: No child processes>
011 : #<Errno::EAGAIN: Resource temporarily unavailable>
012 : #<Errno::ENOMEM: Cannot allocate memory>
013 : #<Errno::EACCES: Permission denied>
014 : #<Errno::EFAULT: Bad address>
015 : #<Errno::ENOTBLK: Block device required>
016 : #<Errno::EBUSY: Device or resource busy>
017 : #<Errno::EEXIST: File exists>
018 : #<Errno::EXDEV: Invalid cross-device link>
019 : #<Errno::ENODEV: No such device>
020 : #<Errno::ENOTDIR: Not a directory>
021 : #<Errno::EISDIR: Is a directory>
022 : #<Errno::EINVAL: Invalid argument>
023 : #<Errno::ENFILE: Too many open files in system>
024 : #<Errno::EMFILE: Too many open files>
025 : #<Errno::ENOTTY: Inappropriate ioctl for device>
026 : #<Errno::ETXTBSY: Text file busy>
027 : #<Errno::EFBIG: File too large>
028 : #<Errno::ENOSPC: No space left on device>
029 : #<Errno::ESPIPE: Illegal seek>
030 : #<Errno::EROFS: Read-only file system>
031 : #<Errno::EMLINK: Too many links>
032 : #<Errno::EPIPE: Broken pipe>
033 : #<Errno::EDOM: Numerical argument out of domain>
034 : #<Errno::ERANGE: Numerical result out of range>
035 : #<Errno::EDEADLK: Resource deadlock avoided>
036 : #<Errno::ENAMETOOLONG: File name too long>
037 : #<Errno::ENOLCK: No locks available>
038 : #<Errno::ENOSYS: Function not implemented>
039 : #<Errno::ENOTEMPTY: Directory not empty>
040 : #<Errno::ELOOP: Too many levels of symbolic links>
042 : #<Errno::ENOMSG: No message of desired type>
043 : #<Errno::EIDRM: Identifier removed>
044 : #<Errno::ECHRNG: Channel number out of range>
045 : #<Errno::EL2NSYNC: Level 2 not synchronized>
046 : #<Errno::EL3HLT: Level 3 halted>
047 : #<Errno::EL3RST: Level 3 reset>
048 : #<Errno::ELNRNG: Link number out of range>
049 : #<Errno::EUNATCH: Protocol driver not attached>
050 : #<Errno::ENOCSI: No CSI structure available>
051 : #<Errno::EL2HLT: Level 2 halted>
052 : #<Errno::EBADE: Invalid exchange>
053 : #<Errno::EBADR: Invalid request descriptor>
054 : #<Errno::EXFULL: Exchange full>
055 : #<Errno::ENOANO: No anode>
056 : #<Errno::EBADRQC: Invalid request code>
057 : #<Errno::EBADSLT: Invalid slot>
059 : #<Errno::EBFONT: Bad font file format>
060 : #<Errno::ENOSTR: Device not a stream>
061 : #<Errno::ENODATA: No data available>
062 : #<Errno::ETIME: Timer expired>
063 : #<Errno::ENOSR: Out of streams resources>
064 : #<Errno::ENONET: Machine is not on the network>
065 : #<Errno::ENOPKG: Package not installed>
066 : #<Errno::EREMOTE: Object is remote>
067 : #<Errno::ENOLINK: Link has been severed>
068 : #<Errno::EADV: Advertise error>
069 : #<Errno::ESRMNT: Srmount error>
070 : #<Errno::ECOMM: Communication error on send>
071 : #<Errno::EPROTO: Protocol error>
072 : #<Errno::EMULTIHOP: Multihop attempted>
073 : #<Errno::EDOTDOT: RFS specific error>
074 : #<Errno::EBADMSG: Bad message>
075 : #<Errno::EOVERFLOW: Value too large for defined data type>
076 : #<Errno::ENOTUNIQ: Name not unique on network>
077 : #<Errno::EBADFD: File descriptor in bad state>
078 : #<Errno::EREMCHG: Remote address changed>
079 : #<Errno::ELIBACC: Can not access a needed shared library>
080 : #<Errno::ELIBBAD: Accessing a corrupted shared library>
081 : #<Errno::ELIBSCN: .lib section in a.out corrupted>
082 : #<Errno::ELIBMAX: Attempting to link in too many shared libraries>
083 : #<Errno::ELIBEXEC: Cannot exec a shared library directly>
084 : #<Errno::EILSEQ: Invalid or incomplete multibyte or wide character>
085 : #<Errno::ERESTART: Interrupted system call should be restarted>
086 : #<Errno::ESTRPIPE: Streams pipe error>
087 : #<Errno::EUSERS: Too many users>
088 : #<Errno::ENOTSOCK: Socket operation on non-socket>
089 : #<Errno::EDESTADDRREQ: Destination address required>
090 : #<Errno::EMSGSIZE: Message too long>
091 : #<Errno::EPROTOTYPE: Protocol wrong type for socket>
092 : #<Errno::ENOPROTOOPT: Protocol not available>
093 : #<Errno::EPROTONOSUPPORT: Protocol not supported>
094 : #<Errno::ESOCKTNOSUPPORT: Socket type not supported>
095 : #<Errno::EOPNOTSUPP: Operation not supported>
096 : #<Errno::EPFNOSUPPORT: Protocol family not supported>
097 : #<Errno::EAFNOSUPPORT: Address family not supported by protocol>
098 : #<Errno::EADDRINUSE: Address already in use>
099 : #<Errno::EADDRNOTAVAIL: Cannot assign requested address>
100 : #<Errno::ENETDOWN: Network is down>
101 : #<Errno::ENETUNREACH: Network is unreachable>
102 : #<Errno::ENETRESET: Network dropped connection on reset>
103 : #<Errno::ECONNABORTED: Software caused connection abort>
104 : #<Errno::ECONNRESET: Connection reset by peer>
105 : #<Errno::ENOBUFS: No buffer space available>
106 : #<Errno::EISCONN: Transport endpoint is already connected>
107 : #<Errno::ENOTCONN: Transport endpoint is not connected>
108 : #<Errno::ESHUTDOWN: Cannot send after transport endpoint shutdown>
109 : #<Errno::ETOOMANYREFS: Too many references: cannot splice>
110 : #<Errno::ETIMEDOUT: Connection timed out>
111 : #<Errno::ECONNREFUSED: Connection refused>
112 : #<Errno::EHOSTDOWN: Host is down>
113 : #<Errno::EHOSTUNREACH: No route to host>
114 : #<Errno::EALREADY: Operation already in progress>
115 : #<Errno::EINPROGRESS: Operation now in progress>
116 : #<Errno::ESTALE: Stale NFS file handle>
117 : #<Errno::EUCLEAN: Structure needs cleaning>
118 : #<Errno::ENOTNAM: Not a XENIX named type file>
119 : #<Errno::ENAVAIL: No XENIX semaphores available>
120 : #<Errno::EISNAM: Is a named type file>
121 : #<Errno::EREMOTEIO: Remote I/O error>
122 : #<Errno::EDQUOT: Disk quota exceeded>
123 : #<SystemCallError: No medium found>
124 : #<SystemCallError: Wrong medium type>
125 : #<SystemCallError: Operation canceled>
cheers.
-a
···
On Fri, 2 Jul 2004, Dick Davies wrote:
* Graham Nicholls <graham@rockcons.co.uk> [0723 13:23]:
Austin Ziegler wrote:
ENOENT is the Unix error, not Ruby's. So, what is the exception for a
missing file on IO.foreach, and how in general can I get a list of
exceptions or find out which is the right one to use?
Try rescuing Errno::ENOENT.
Out of interest, is there anyway of knowing what exceptions a given
class can raise?
I'd expect not, but I've been wrong before (as any regulars on this list
will know).
--
EMAIL :: Ara [dot] T [dot] Howard [at] noaa [dot] gov
PHONE :: 303.497.6469
A flower falls, even though we love it;
and a weed grows, even though we do not love it. --Dogen
"Austin Ziegler" <halostatue@gmail.com> schrieb im Newsbeitrag
news:9e7db91104070206039eee67a@mail.gmail.com...
> Out of interest, is there anyway of knowing what exceptions a given
> class can raise?
>
> I'd expect not, but I've been wrong before (as any regulars on this
list
> will know).
As far as I know, no. However, I have also read that the "promised"
list of exceptions (cf Java) is more problematic than useful (ISTR
something on Joel on Software about it). However, using the classtree
method (http://www.rubygarden.org/ruby?ASCIIClassHierarchyGenerator\),
you can call:
class_tree(Exception, false, false)
And get a tree of possible exceptions. That's where I found
Errno::ENOENT.
In this case catching Exception should have helped, too. Or am I missing
something?
begin
File.open("not possibly found here")
rescue Exception => e
p e
puts e.class
end
Yields this in IRB:
irb(main):001:0> begin
irb(main):002:1* File.open("not possibly found here")
irb(main):003:1> rescue Exception => e
irb(main):004:1> p e
irb(main):005:1> puts e.class
irb(main):006:1> end
#<Errno::ENOENT: No such file or directory - not possibly found here>
Errno::ENOENT
=> nil
Regards
robert
···
On Fri, 2 Jul 2004 21:48:45 +0900, Dick Davies > <rasputnik@hellooperator.net> wrote:
In this case catching Exception should have helped, too. Or am I missing
something?
begin
File.open("not possibly found here")
rescue Exception => e
p e
puts e.class
end
This will work, but catch-all rescue blocks like that can be
dangerous, as they can mask user interrupts, missing method errors,
etc. Using the most specific exception class that still covers the
errors you expect to see in a block means that unexpected errors will
be thrown up to higher levels on the stack, which is exactly what
should happen.
Lennon
···
On Fri, 2 Jul 2004 23:32:47 +0900, Robert Klemme <bob.news@gmx.net> wrote:
"Lennon Day-Reynolds" <rcoder@gmail.com> schrieb im Newsbeitrag
news:5d4c6124040702163941cbd3c7@mail.gmail.com...
[...]
> In this case catching Exception should have helped, too. Or am I
missing
> something?
>
> begin
> File.open("not possibly found here")
> rescue Exception => e
> p e
> puts e.class
> end
This will work, but catch-all rescue blocks like that can be
dangerous, as they can mask user interrupts, missing method errors,
etc. Using the most specific exception class that still covers the
errors you expect to see in a block means that unexpected errors will
be thrown up to higher levels on the stack, which is exactly what
should happen.
Of course you are right, but this code snippet was just meant to determine
the proper type. I was responding to another suggestion how to find the
type of this exception. This was not meant to be program code.
Regards
robert
···
On Fri, 2 Jul 2004 23:32:47 +0900, Robert Klemme <bob.news@gmx.net> wrote:
In Message-Id: <2kseplF5p2cpU1@uni-berlin.de>
"Robert Klemme" <bob.news@gmx.net> writes:
Of course you are right, but this code snippet was just meant to determine
the proper type. I was responding to another suggestion how to find the
type of this exception. This was not meant to be program code.
Actually no extra code is needed in this case:
> ruby -e 'File.open("no_such_file")'
-e:1:in `initialize': No such file or directory - no_such_file (Errno::ENOENT)
from -e:1:in `open'
from -e:1
As you can see, a class of an exception raised is showed in () of the
message.
Just FYI.
···
--
kjana@dm4lab.to July 5, 2004
Never put off till tomorrow what you can do today.